Acetonemic vomiting occurs primarily with psychologically and vegetatively labile infants and is often prompted by wrong diet, food allergy, an infestation with worms or infections. After an initial headache accompanied with lack of appetite and nausea, the body starts to excrete acetone into the breathing air and urine. Simultaneously, the infant suffers from vigorous, often uncontrollable vomiting, apathy, heavy breathing and exsiccosis. Characteristic for this disease is a metabolic acidosis accompanying the increase of acetone which is caused by overproduction and insufficient consumption of acetyl-CoA. There is even the risk that the child falls in a so-called ketonemic coma.
Acetonemic vomiting is currently diagnosed by regular pH-measurements of the child's urine. The procedure employed is relatively cumbersome and is felt to be a burden by both the parents using it and the children suffering from the disease. The child has to collect its urine in a container. Then, an indicator strip is dipped into the container to evaluate the pH value (acidity level) of the urine. Often, it is only the outer tip of this strip, into which the pH indicator is incorporated, which makes it more difficult to determine potential colour changes correctly and precisely.
Moreover, there are other diseases like diabetes where the pH of urine can be taken as a signal for the state of the patient and a correctly applied therapy.
U.S. Pat. No. 5,769,813 describes a tampon applicator comprising a pH indicator for testing excreted biological fluids. It is stated that this tampon serves for determining the pH balance of biological fluid excreted from the vaginal cavity to detect the presence of undesired bacterial activity.
EP 1 043 377 A2 discloses a wetness indicating hot melt adhesive and a disposable product including diapers and sanitary napkins containing the same. It is explained that in such disposable products it is desirable to know if the product has become wet with water or urine. The hot melt adhesive comprises as essential components    a) 20 to 80 wt % of sulfonated polyester,    b) 3 to 30 wt % of acidic plasticizer; and    c) 0.05 to 3 wt % of an indicating agent capable of changing colour in response to changes in pH.
A wetness indicating holt melt adhesive is also the subject matter of U.S. Pat. No. 4,681,576. The adhesive contains 20 to 70 wt % of polymer, 35 to 100 wt % of which is water sensitive polymer; 27 to 60 wt % of organic acid and 0 to 30 wt % of water-soluble wax and wetness indicating agent which changes the color of the composition rapidly in response to moisture therein.
Correspondingly, it is one technical object of the present invention to provide a simplified diagnostic tool for detecting and monitoring pH changes in the urine as caused by metabolic and/or physiological disorders, such as acetonemic vomiting or diabetes. Other technical objects will become apparent from the following more detailed description of the invention.